Sporadic communication protocol between clusters of mobile computers

Recently, mobile computers such as laptop, handheld and parmtop PCs have become to communicate with each other by using wireless LAN protocols, e.g., IEEE802.11 and HIPERLAN. Conventional routing protocols support a mobile network in which mobile computers change their location independently. In case that a mobile computer changes the location with high speed, less messages are exchanged between the mobile computers. In this paper, the authors propose a novel routing protocol for supporting mobile clustered networks in which mobile computers move with almost the same velocity and communicate with each other by multi-hop message transmission form a cluster. Here, communication between clusters is available if at least one mobile computer in the cluster is within the message transmission range of a mobile computer in the other cluster. That is, a communication protocol is required to support sporadic communication. For achieving higher bandwidth even though the clusters move with high speed, a set of gateway mobile computers are introduced in each cluster. We design protocols for switching gateways and for updating routing tables in the clusters according to the movement.